BYK W 966 is a wetting and dispersing additive that reduces viscosity and prevents settling of fillers in filled unsaturated polyester resins, acrylic, PU and epoxy resins. BYK W 966 improves the dispersion of conventional fillers like calcium carbonate and aluminum hydroxide. This allows higher filling levels in the resin and reduces settling during storage and processing. BYK W 966 is especially suitable for fiber reinforced spray-up and hand lay-up resins used in construction applications. It also can be used in cobalt-accelerated putty compounds for construction. BYK W 966 provides benefits like lowering viscosity, improving wetting of fillers and reducing sedimentation of fillers in different resin systems.